Trap balloon catheter with trap balloon retainer

ABSTRACT

Medical devices, medical device systems, and methods for using the same are disclosed. An example medical device system may include a guide catheter having a proximal end, a distal end, and a lumen extending therebetween. The guide catheter may be designed to guide a therapeutic catheter to a target site. A guidewire may be disposed within the lumen of the guide catheter. The system may also include a trap balloon catheter including a catheter shaft and a balloon coupled to the catheter shaft. The trap balloon catheter may be designed to extend through the lumen of the guide catheter to a position adjacent to the distal end of the guide catheter. A trap balloon retainer may be coupled to the catheter shaft. The trap balloon retainer may be designed to prevent a distal end of the trap balloon catheter from extending distally beyond the distal end of the guide catheter.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/093,889, filed Apr. 8, 2016, which claims the benefit of and priorityto U.S. Provisional Patent Application No. 62/279,983, filed Jan. 18,2016 and to U.S. Provisional Patent Application No. 62/145,496, filedApr. 9, 2015, the disclosures of which are incorporated herein byreference.

TECHNICAL FIELD

The present disclosure pertains to medical devices, and methods formanufacturing medical devices. More particularly, the present disclosurepertains to trap balloon catheters.

BACKGROUND

A wide variety of intracorporeal medical devices have been developed formedical use, for example, intravascular use. Some of these devicesinclude guidewires, catheters, and the like. These devices aremanufactured by any one of a variety of different manufacturing methodsand may be used according to any one of a variety of methods. Of theknown medical devices and methods, each has certain advantages anddisadvantages. There is an ongoing need to provide alternative medicaldevices as well as alternative methods for manufacturing and usingmedical devices.

BRIEF SUMMARY

This disclosure provides design, material, manufacturing method, and usealternatives for medical devices. A medical device system is disclosed.The medical device system includes a guide catheter having a proximalend, a distal end, and a lumen extending therebetween. The guidecatheter is designed to guide a therapeutic catheter to a target site.The system may also include a guidewire disposed within the lumen of theguide catheter and a trap balloon catheter including a catheter shaftand a balloon coupled to the catheter shaft. The trap balloon catheteris designed to extend through the lumen of the guide catheter to aposition adjacent to the distal end of the guide catheter. The balloonis designed to be expanded in order to secure the position of theguidewire relative to the guide catheter by securing the guidewirebetween the balloon and an inner surface of the guide catheter. The trapballoon catheter includes a trap balloon retainer coupled to thecatheter shaft. The trap balloon retainer is designed to prevent adistal end of the trap balloon catheter from extending distally beyondthe distal end of the guide catheter.

Alternatively or additionally to any of the embodiments above, the trapballoon retainer includes a slidable member slidably disposed along thecatheter shaft and a sheath, the slidable member having a proximal endregion disposed within the sheath.

Alternatively or additionally to any of the embodiments above, theslidable member includes a first stop designed to abut a proximal endregion of the guide catheter and a second stop.

Alternatively or additionally to any of the embodiments above, thesheath has a distal end region with a reduced outer diameter, andwherein the second stop is positioned proximally of the distal endregion.

Alternatively or additionally to any of the embodiments above, thesheath has a landing region, and wherein the second stop is designed toseat with the landing region.

Alternatively or additionally to any of the embodiments above, the trapballoon retainer includes a tube releasably secured to the cathetershaft.

Alternatively or additionally to any of the embodiments above, the trapballoon retainer includes an axial slit, an axial score line, or both.

Alternatively or additionally to any of the embodiments above, the trapballoon retainer includes a proximal tubular member and a distal tubularmember.

Alternatively or additionally to any of the embodiments above, theproximal tubular member abuts the distal tubular member.

Alternatively or additionally to any of the embodiments above, aproximal region of the distal tubular member is disposed within a distalregion of the proximal tubular member.

An example method for catheter exchanges is disclosed. The methodincludes positioning a guide catheter within a body lumen and advancinga guidewire through the guide catheter. A first therapeutic catheter isadvanced over the guidewire and through the guide catheter to a targetregion. A trap balloon catheter is subsequently advanced through theguide catheter. The trap balloon catheter includes a catheter shaft, aballoon coupled to the catheter shaft, and a trap balloon retainercoupled to the catheter shaft. The balloon is inflated to secure theguidewire between the balloon and an inner surface of the guide catheterand then the first therapeutic catheter is retracted from the guidecatheter. Thereafter, a second therapeutic catheter is advanced over theguidewire and through the guide catheter.

Alternatively or additionally to any of the embodiments above, furthercomprising removing the trap balloon retainer from the catheter shaft.

Alternatively or additionally to any of the embodiments above, the trapballoon retainer includes a tubular member releasably secured to thecatheter shaft.

Alternatively or additionally to any of the embodiments above, the trapballoon retainer includes a slidable member slidably disposed along thecatheter shaft and a sheath, the slidable member having a proximal endregion disposed within the sheath.

Alternatively or additionally to any of the embodiments above, furthercomprising sliding the slidable member along the catheter shaft toadjust the length of the catheter shaft extending through the guidecatheter.

Alternatively or additionally to any of the embodiments above, theslidable member includes a first stop and a second stop, wherein thefirst stop is positioned distal of the sheath and the second stop ispositioned within the sheath.

Alternatively or additionally to any of the embodiments above, thesheath has a distal end region with a reduced outer diameter, andwherein the sheath has a landing region disposed proximally of thedistal end region.

Alternatively or additionally to any of the embodiments above, slidingthe slidable member along the catheter shaft to adjust the length of thecatheter shaft extending through the guide catheter includes sliding thefirst stop to a position adjacent to adjacent to the distal end regionof the sheath.

Alternatively or additionally to any of the embodiments above, slidingthe slidable member along the catheter shaft to adjust the length of thecatheter shaft extending through the guide catheter includes sliding thesecond stop to a position adjacent to adjacent to the distal end regionof the sheath.

Alternatively or additionally to any of the embodiments above, slidingthe slidable member along the catheter shaft to adjust the length of thecatheter shaft extending through the guide catheter includes sliding thesecond stop to the landing region of the sheath.

An example trap balloon catheter is disclosed. The trap balloon catheterincludes a catheter shaft extending distally from a hub of the catheterto a distal tip of the catheter. The catheter shaft has an overalllength measured from the hub to the distal tip. A trap balloon isattached to a distal end region of the catheter shaft. The trap balloonis designed to be expanded within a guide catheter to secure a guidewirebetween the trap balloon and an inner surface of the guide catheter. Atrap balloon retainer is coupled to the catheter shaft. The trap balloonretainer includes a slidable member slidably disposed along the cathetershaft between a first position providing the catheter with a firstworking length and a second position providing the catheter with asecond working length greater than the first working length. The firstworking length is compatible with a first guide catheter length suchthat the trap balloon is prevented from being positioned distal of adistal end of the guide catheter when the catheter shaft is fullyadvanced distally through the guide catheter up to the first workinglength. The second working length is compatible with a second guidecatheter length such that the trap balloon is prevented from beingpositioned distal of the distal end of the guide catheter when thecatheter shaft is fully advanced distally through the guide catheter upto the second working length. The overall length of the catheter shaftwhen the slidable member is at the first position is the same as theoverall length of the catheter shaft when the slidable member is at thesecond position.

Alternatively or additionally to any of the embodiments above, furthercomprising a sheath surrounding a portion of the catheter shaft, whereina proximal portion of the slidable member is slidably disposed withinthe sheath.

Alternatively or additionally to any of the embodiments above, furthercomprising a first stop located on a proximal end region of the slidablemember and a second stop located on a distal end region of the slidablemember, wherein the first stop is positioned distal of the sheath andthe second stop is positioned within the sheath.

Alternatively or additionally to any of the embodiments above, thesheath has a distal end region with a reduced outer diameter, and thesheath has a landing region disposed proximally of the distal endregion.

The above summary of some embodiments is not intended to describe eachdisclosed embodiment or every implementation of the present disclosure.The Figures, and Detailed Description, which follow, more particularlyexemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more completely understood in consideration of thefollowing detailed description in connection with the accompanyingdrawings, in which:

FIG. 1 is a plan view of an example medical device system;

FIG. 2 is a plan view of an example medical device system;

FIG. 3 is a plan view of an example medical device system;

FIG. 4 is a plan view of an example medical device system;

FIG. 5 is a side view of an example trap balloon catheter;

FIG. 6 is a side view of an example trap balloon catheter;

FIG. 7 is a side view of an example trap balloon catheter;

FIG. 8 is a side view of an example trap balloon catheter;

FIG. 9 is a side view of an example trap balloon catheter;

FIG. 10 is a side view of an example trap balloon catheter;

FIG. 11 is a side view of an example trap balloon catheter;

FIG. 12 is a side view of the example trap balloon catheter of FIG. 11and an example guide catheter;

FIG. 13 is a side view of the example trap balloon catheter of FIG. 11having a first working length;

FIG. 14 is a side view of the example trap balloon catheter of FIG. 11having a second working length; and

FIG. 15 is a side view of the example trap balloon catheter of FIG. 11having a third working length.

While the disclosure is amenable to various modifications andalternative forms, specifics thereof have been shown by way of examplein the drawings and will be described in detail. It should beunderstood, however, that the intention is not to limit the invention tothe particular embodiments described. On the contrary, the intention isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the disclosure.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about”, whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (e.g., having the same function orresult). In many instances, the terms “about” may include numbers thatare rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and5).

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

It is noted that references in the specification to “an embodiment”,“some embodiments”, “other embodiments”, etc., indicate that theembodiment described may include one or more particular features,structures, and/or characteristics. However, such recitations do notnecessarily mean that all embodiments include the particular features,structures, and/or characteristics. Additionally, when particularfeatures, structures, and/or characteristics are described in connectionwith one embodiment, it should be understood that such features,structures, and/or characteristics may also be used connection withother embodiments whether or not explicitly described unless clearlystated to the contrary.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The drawings, which are not necessarily to scale, depictillustrative embodiments and are not intended to limit the scope of theinvention.

A number of minimally invasive intravascular procedures have beendeveloped. Some of these procedures includes balloon angioplasty and/orthe delivery of intravascular stents. At least some of these proceduresutilize a guide catheter to help “guide” a therapeutic device to atarget. The use of a guide catheter may include advancing the guidecatheter through a body lumen (e.g., blood vessel) to a position near atarget, advancing a guidewire through the guide catheter, and advancingthe therapeutic catheter over the guidewire toward the target. In someinstances, it may be desirable to remove the therapeutic catheter andthen advance a different therapeutic catheter toward the target. For anumber of reasons it may be desirable to maintain the position of theguidewire (which may be desirably positioned relative to the target)during the catheter exchange.

The devices and method disclosed herein are aimed at help to facilitatecatheter exchanges. For example, the devices and methods disclosedherein may be designed to help maintain the position of a guidewireduring a catheter exchange. Furthermore, the devices and methodsdisclosed herein may utilize a “retainer” and/or “retainer mechanism”that may allow the devices disclosed herein to be used with differentlysized guide catheters. Some of the details regarding these devices andmethods are disclosed herein.

FIG. 1 illustrates an example medical device system 10. System 10 mayinclude a number of different components. For example, system 10 mayinclude a guide catheter 11 and a treatment catheter 18 extendablethrough guide catheter 11. Guide catheter 11 may resemble typical guidecatheters. For example, guide catheter 11 may include a catheter shafthaving a proximal end (not shown), a distal end 15, and defining a lumen13 extending at least partially therebetween. A hub assembly (not shown)may be disposed at the proximal end. In use, guide catheter 11 may beadvanced through a body lumen or blood vessel 12. In this example, guidecatheter 11 is shown disposed within the aorta 12. Other blood vesselsand/or body lumens are contemplated. A guidewire 14 may be advancedthrough or otherwise disposed within lumen 13 of guide catheter 11.Guidewire 14 may extend through the aorta 12 and into a target region16. In this example, target region 16 is a coronary artery. Other targetregions are contemplated.

Treatment catheter 18 may extend through guide catheter 11 (e.g.,through lumen 13 formed in guide catheter 11) to a position adjacent toor within target region 16 as shown in FIG. 2. This may includeadvancing treatment catheter 18 over guidewire 14. Treatment catheter 18may take a variety of different forms. For example, treatment catheter18 may take the form of a balloon catheter, a stent delivery system, orthe like. Treatment catheter 18 may be used for its intended purpose.For example, if treatment catheter 18 is a stent delivery system,treatment catheter 18 may be used to deliver a stent.

In some instances, it may be desirable to remove treatment catheter 18and advance a new or different treatment catheter (e.g., a secondtreatment catheter) over guidewire 14. During the removal of treatmentcatheter 18 (i.e., first treatment catheter) and/or the advancement ofanother treatment catheter (e.g., a second treatment catheter), it maybe desirable to secure the position of guidewire 14. In order to helpsecure the position of guidewire 14, a trap balloon catheter 20 may beadvanced through lumen 13 of guide catheter 11 as shown in FIG. 3 withguidewire 14 exterior of trap balloon catheter 20.

Trap balloon catheter 20 may include a catheter shaft 22 and a balloon24. Trap balloon catheter 20 may be advanced through lumen 13 of guidecatheter 11 while or after treatment catheter 18 is at least partiallyretracted so that balloon 24 may be positioned distally of the distalend of treatment catheter 18. This may allow trap balloon catheter 20 tobe properly positioned so that trap balloon catheter 20 can effectivelytrap guidewire 14 within lumen 13 of guide catheter 11 while alsoallowing treatment catheter 18 to still be removed. When suitablypositioned, balloon 24 may be expanded to trap guidewire 14 betweenballoon 24 and an inner surface 25 of lumen 13 of guide catheter 11 asshown in FIG. 4.

When using a trap balloon catheter, such as trap balloon catheter 20, itmay be desirable keep balloon 24 from extending beyond the distal end 15of guide catheter 11. One potential way to keep balloon 24 fromextending beyond the distal end 15 of guide catheter 11 is to size trapballoon catheter 20 so that it is “compatible” with a desired guidecatheter, such as guide catheter 11. In other words, when using trapballoon catheter 20 with a 90 cm guide catheter 11, catheter shaft 22may have a length that is sized so that balloon 24 is substantiallyprevented from extending beyond the distal end of guide catheter 11(e.g., catheter shaft 22 may have a working length extendable throughguide catheter 11 that is less than 90 cm). In some instances, the hubassembly (e.g., which may be disposed at the proximal end of trapballoon catheter 20) may function as a physical barrier that issufficiently enlarged relative to the lumen of guide catheter 11 so asto prevent trap balloon catheter 20 from advancing too far within guidecatheter 11.

It can be appreciated that if sizing, alone, is relied upon for ensuringcompatibility of trap balloon catheter 20 with guide catheter 11, anumber of differently sized trap balloon catheters 20 may be separatelyprovided for use with each of the differently sized guide catheters.While effective, it may be desirable to have a single sized trap ballooncatheter 20 that is compatible with a number of differently sized guidecatheters.

FIG. 5 illustrates trap balloon catheter 20. As indicated above, trapballoon catheter 20 includes catheter shaft 22 and balloon 24. A hubassembly 28 may be coupled to catheter shaft 22. Trap balloon catheter20 includes a trap balloon retainer 26. Trap balloon retainer 26 isdesigned to allow trap balloon catheter 20 to be compatible withdifferently sized guide catheters. For example, trap balloon retainer 26may be positioned along catheter shaft 22 and may function as a physicalbarrier that is designed to keep balloon 24 from extending beyond thedistal end of a guide catheter (e.g., guide catheter 11). For example,the diameter of trap balloon retainer 26 may be larger than the innerdiameter and/or outer diameter of the guide catheter. In otherinstances, trap balloon retainer 26 need only be larger than the innerdiameter of guide catheter minus the other products expected to be inthe guide catheter (e.g., the guidewire being trapped).

In some instances, trap balloon catheter 20 may take the form of a fixedwire catheter. A fixed wire catheter may provide enhanced kinkresistance. In other instances, trap balloon catheter 20 may be anover-the-wire catheter that includes a guidewire lumen. In still otherinstances, trap balloon catheter 20 may be a single-operator-exchangecatheter with a shortened guidewire lumen.

Retainer 26 may be releasably coupled to catheter shaft 22. Whenretainer 26 is disposed along catheter shaft 22, trap balloon catheter20 may be compatible with a first guide catheter having a first length(e.g., a “short” guide catheter that may have a length, for example, ofabout 90 cm). When/if desired, retainer 26 may be removed from cathetershaft 22 to convert trap balloon catheter 20 so that it is compatiblewith a second guide catheter having a second length that is longer thanthe first length (e.g., a “long” guide catheter that may have a length,for example, of about 100 cm).

In some instances, retainer 26 may be a component that is packaged alongwith trap balloon catheter 20 in either an attached configuration (e.g.,where retainer 26 is positioned along catheter shaft 22) or anunattached configuration (e.g., where retainer 26 is contained within apackage along with or otherwise provided with trap balloon catheter 20).Retainer 26 may be labeled with a compatibly message (e.g., “compatiblewith a 90 cm guide catheter, remove for use with a 100 cm guidecatheter” or the like), color coded, noted in the instructions for use,and/or otherwise bear a signal or message that communicatescompatibility.

FIG. 6 illustrates an example trap balloon retainer 126, similar in formand function to trap balloon retainer 26 disclosed herein. In thisexample, retainer 126 includes an axial score line 128. Score line 128may allow for retainer 126 to be more easily split to as to facilitateremoval. In some instances, retainer 126 may include a single slot scoreline 128, such as an axial score line. In other instances, retainer 126may include a plurality of score lines 128. In still other instances,retainer 126 may include a structural feature such as a tab or handle(not shown) that allows retainer 126 to be peeled away from cathetershaft 22.

FIG. 7 illustrates an example trap balloon retainer 226, similar in formand function to trap balloon retainer 26 disclosed herein. In thisexample, retainer 226 includes a slot 230, such as an axial slot. Justlike score line 128, slot 230 may allow retainer 226 to be more easilyremoved from catheter shaft 22. In some instances, retainer 226 mayinclude a single slot 230. In other instances, retainer 226 may includea plurality of slots 230.

FIG. 8 illustrates an example trap balloon retainer 326, similar in formand function to trap balloon retainer 26 disclosed herein. In thisexample, retainer 326 includes a first tubular member 328 a and a secondtubular member 328 b. Other retainers are also contemplated that includeadditional tubular members. The use of multiple tubular members mayincrease the compatibility of retainer 326 with even more guidecatheters. For example, having both tubular members 328 a/328 b attachedto catheter shaft 22 may provide compatibility with a first guidecatheter. Removing one tubular member (e.g., second tubular member 328b) may provide compatibility with a second (e.g., longer) guidecatheter. Removing both first and second tubular members 328 a/328 b mayprovide compatibility with a third (e.g., longer yet) guide catheter. Insome instances, first and second tubular members 328 a/328 b may becolor coded in order to more clearly communicate compatibility to auser.

FIG. 9 illustrates an example trap balloon retainer 426, similar in formand function to trap balloon retainer 26 disclosed herein. In thisexample, retainer 426 includes a first tubular member 428 a and a secondtubular member 428 b. Other retainers are also contemplated that includeadditional tubular members. Second tubular member 428 b may include anecked down region 432 that is designed to be positioned within firsttubular member 428 b. Alternatively, first tubular member 428 a mayinclude necked down region 432 to be positioned within second tubularmember 428 b. Similar to retainer 326, the use of multiple tubes mayenhance the compatibility of retainer 426 with differently sized guidecatheters.

FIG. 10 illustrates an example trap balloon retainer 526, similar inform and function to trap balloon retainer 26 disclosed herein. In thisexample, retainer 526 is in the form of a clamp. Clamp 526, which isshown schematically, may vary in form. For example, clamp 526 may takethe form of a c-clamp. Other forms are contemplated. In some instances,clamp 526 may be disposed at a first position along catheter shaft 22 soas to provide compatibility with a first guide catheter. The firstposition may be marked or labeled with a suitable marking. Clamp 526 maybe movable to a second position along catheter shaft 22 so as to providecompatibility with a second guide catheter. The second position may alsobe marked or labeled with a suitable marking.

FIG. 11 illustrates an example trap balloon catheter 620 that may besimilar in form and function to other trap balloon catheters disclosedherein. Trap balloon catheter 620 includes catheter shaft 622 andballoon 624 coupled to a distal end region of catheter shaft 622 (e.g.,adjacent to a distal end of catheter shaft 622). Hub 628 may be coupledto catheter shaft 622 (e.g., attached adjacent to a proximal end ofcatheter shaft 622). Thus, catheter shaft 622 may be secured to hub 628and extend distally therefrom to a distal tip of catheter shaft 622.

The form, configuration, and/or sizing of the components of trap ballooncatheter 620 may vary. For example, in some instances balloon 624 mayhave a diameter of about 1 mm to about 4 mm or about 2 mm to about 3 mm,for example. In some instances, the diameter of balloon 624 may be about2.4 mm +/−0.1 mm or about 2.5 mm +/−0.2 mm. In general, balloon 624 maybe sized so that trap balloon catheter 620 may be used with a full rangeof differently sized guide catheters (e.g., 6F-8F guide catheters). Inaddition, balloon 624 may be a relatively high pressure balloon. Inother words, balloon 624 may be designed to withstand relatively highinflation pressures. For example, balloon 624 may be inflated to apressure of about 10-14 atm (e.g., 12 atm) and may have a rated burstpressure of about 18-22 atm (e.g., about 20 atm).

In some instances trap balloon catheter 620 may include rounded tip 625(e.g., as shown in FIGS. 11 and 13-15). Rounded tip 625 may take theform of a metal ball formed as a ball weld at the distal end of trapballoon catheter 620 (e.g., on a distal end of a wire 627). Rounded tip625 may have a diameter greater than or equal to about 0.019 inches(0.048 cm) or a diameter on the order of about 0.018-0.026 inches(0.046-0.066 cm). In some instances, wire 627 may have a diameter ofabout 0.012 inches (0.0305 cm). Wire 627 may also include about 10 mm orso of a more flexible proximal section having a diameter of about 0.008inches (0.020 cm). These sizes may be compatible with a variety of guidecatheters (e.g., 6F-8F guide catheters) and may help to reduce thepossibility of the distal end of trap balloon catheter 620 (e.g.,adjacent rounded tip 625) catching, perforating a vessel, or damaginganother interventional device positioned within the guide catheterduring a trapping procedure or during device exchanges.

Trap balloon catheter 620 may include one or more radiopaque markers.For example, trap balloon catheter 620 may include a first radiopaquemarker 629 a, a second radiopaque marker 629 b, or both. Markers 629a/629 b may be disposed within balloon 624 along shaft 622. In at leastsome instances, markers 629 a/629 b may include radiopaque materialssuch as, for example, platinum and/or iridium. Other materials may alsobe utilized. Markers 629 a/629 b may have a length, thickness, or boththat is greater than that of markers typically utilized with otherdevices such as guide catheters. For example, one or both of markers 629a/629 b may have a length on the order of about 2 mm (e.g., which may beabout twice as long as markers used with other devices) and may have athickness of about 0.002 inches (0.005 cm; which may be about twice asthick as markers used with other devices). By increasing the lengthand/or thickness of markers 629 a/629 b, the relative opacity may beincreased, thereby increasing the ability of clinician to visualizemarkers 629 a/629 b, for example when trap balloon catheter 620 ispositioned within a guide catheter (which could otherwise “dilute” therelative radiopacity of trap balloon catheter 620). Furthermore, theincreased length and/or thickness may also help a clinician to betterdifferentiate trap balloon catheter 620 from other radiopaque structuresincluding shorter and/or thinner markers, braids or coils, or the like.In an example, radiopaque markers 629 a/629 b may be the same ordifferent size.

Just like the other trap balloon catheters disclosed herein, trapballoon catheter 620 is designed to be compatible with guide cathetersof differing lengths. For example, trap balloon catheter 620 includestrap balloon retainer 626 that is designed to allow for the workinglength of catheter shaft 622 that extends into a guide catheter to beadjusted so that balloon 624 can be prevented from extending distallybeyond the distal end of the guide catheter and so that trap ballooncatheter 620 can be used with guide catheters of differing lengths. Inother words, trap balloon catheter 620 includes a trap balloon retainer626 that may be actuated by the user between one of a plurality ofdiscrete positions to adjust the working length of trap balloon catheter620 between one of a plurality of different working lengths. Thus, themaximum distance trap balloon catheter 620 can extend into a guidecatheter 11, shown in FIG. 12, (e.g., the maximum distance trap ballooncatheter 620 can extend through the lumen of guide catheter 11 from theproximal hub of guide catheter 11) may be adjusted based on the lengthof guide catheter 11 such that balloon 624 may be maintained within thelumen of guide catheter 11 when trap balloon catheter 620 is fullyinserted into guide catheter 11 (e.g., when advanced into lumen of guidecatheter 11 up to the full working length).

Retainer 626 may include a slidable member 634 and, in some instances, asheath 640. Slidable member 634 may be configured to longitudinallyslide relative to catheter shaft 622 and/or hub 628 between a pluralityof discrete positions, such as first, second and third positions, asdescribed further below. In some instances, slidable member 634 is atelescoping tube surrounding catheter shaft 622 and longitudinallyslidable thereover. Slidable member 634 may include one or more stops,such as a first stop 636 and a second stop 638. First stop 636 may belocated at distal end of slidable member 634. In some instances, firststop 636 may be secured to distal end of slidable member 634, or firststop 636 may be formed as a unitary portion of slidable member 634.First stop 636 may be designed to abut a proximal end of a guidecatheter (e.g., the hub of the guide catheter) and prevent trap ballooncatheter 620 from extending any further distally into the lumen of theguide catheter. In other words, first stop 636 may be a physical barrierthat stops or limits the working length of catheter shaft 622 thatextends into the lumen of the guide catheter while the overall length ofthe trap balloon catheter 620 (i.e., the length from the hub 628 to thedistal tip of catheter shaft 622) is fixed regardless of the position offirst and second stops 636/638 and/or slidable member 634. Trap ballooncatheter 620 can be adjusted by sliding slidable member 634 alongcatheter shaft 622. For example, slidable member 634 may be adjusted toor otherwise disposed in a first position that is compatible for usewith a first guide catheter having a first length and adjusted to asecond position that is compatible for use with a second guide catheterhaving a second length, different than the first length (e.g., thesecond length may be greater than the first length). Thus, slidingslidable member 634 to one of a plurality of longitudinal positionsallows for trap balloon catheter 620 to be used with guide cathetershaving different lengths, while keeping balloon 624 from extendingdistally beyond the distal end of the guide catheter when the trapballoon catheter 620 is inserted into the lumen of the guide catheter upto the full working length of the trap balloon catheter 620.

Sheath 640 may be disposed along catheter shaft 622 and may take theform of a tubular member that is coupled to or fixed relative to hub 628and extends distally from hub 628 along catheter shaft 622. Sheath 640may surround catheter shaft 622 to define an annular space 635 betweenthe outer surface of catheter shaft 622 and the inner surface of sheath640. A proximal end region of slidable member 634, including second stop638, may extend into sheath 640 through a distal opening of sheath 640,with a distal end region of slidable member 634, including first stop636 extending distal of sheath 640. Slidable member 634 maylongitudinally slide along catheter shaft 622 relative to sheath 640,which may be fixed relative to catheter shaft 622.

Sheath 640 may have a body region 642 and a distal end region 644. Insome instances, distal end region 644 may have a reduced outer diameter(e.g., the outer diameter of distal end region 644 may be reducedrelative to the outer diameter of body region 642). Additionally oralternatively, the inner diameter of distal end region 644 may bereduced relative to the inner diameter of the body region 642. Sheath640 may also include a stop, such as a landing region 646, in someinstances. Landing region 646 may take the form of a slight reduction inthe inner diameter of sheath 640 (e.g., necked down region of sheath640) that forms a physical barrier for further proximal movement ofsecond stop 638 within sheath 640. In other instances, landing region646 may have a different configuration, such as one or more protrusionsconfigured to restrict proximal movement of second stop 638 past landingregion 646. Thus, second stop 638 may be partially “locked” or otherwisestopped from moving further proximally by contact with landing region646. However, in at least some instances, a user may apply additionalforce to slidable member 634 in order to further slide slidable member634 proximally within sheath 640 such that second stop 638 is movedproximally past landing region 646.

In use, retainer 626 may be oriented so that second stop 638 (which islocated at the proximal end region of slidable member 634, such assecured to or unitarily formed with the slidable member 634) is disposedwithin sheath 640 and positioned proximally of distal end region 644. Insome instances, the size reduction in sheath 640 at distal end region644 (e.g., of outer diameter, inner diameter, or both) may be less thanthe outer diameter of second stop 638 to effectively “lock” second stop638 within sheath 640 and, thus, limit the distal movement of slidablemember 634. First stop 636 (which is located at the distal end region ofslidable member 634, such as secured to or unitarily formed with theslidable member 634, and positioned exterior to sheath 640) may bepositioned distally of distal end region 644. First stop 636 may abutthe proximal end and/or hub 13 of guide catheter 11 as shown in FIG. 12when trap balloon catheter 620 is fully inserted into guide catheter 11.Because of this, the working length of catheter shaft 622 extending intoguide catheter 11 corresponds to the length of catheter shaft 622 thatis distal of first stop 636. Adjusting the position of slidable member634 and, thus, the position of first stop 636 along catheter shaft 622adjusts the working length of catheter shaft 622 permitted to extendinto guide catheter 11.

At least some of the adjustable lengths of catheter shaft 622 (e.g., thelength of catheter shaft 622 that can extend into catheter shaft 11 inorder to keep balloon 624 from extending beyond the distal end of guidecatheter 11) that can be accomplished using retainer 626 are shown inFIGS. 13-15. For example, slidable member 634 may be positioned at afirst position where second stop 638 is positioned adjacent to orotherwise abuts distal end region 644 as shown in FIG. 13. The firstposition may be a position in which slidable member 634 is at itsdistalmost extent. This defines a first working length L1 of cathetershaft 622 that can extend into guide catheter 11. In some instances,first working length L1 may correspond to the shortest working length ofcatheter shaft 622 that can extend into guide catheter. Thus, whenretainer 626 is oriented as shown in FIG. 13, trap balloon catheter 620may be compatible with a first guide catheter having a working length(e.g., a 90 cm guide catheter). When slidable member 634 is positionedat the first position (corresponding to use of trap balloon catheter 620with a guide catheter having a specified working length (e.g., a 90 cmguide catheter)), full working length L1 of trap balloon catheter 620can be inserted into the lumen of the guide catheter having thespecified working length while the balloon 624 remains within the lumenof the guide catheter and is prevented from extending out the distal endof the guide catheter. Regardless of the working length (e.g., firstworking length L1) and/or position of slidable member 634, an overalllength X of trap balloon catheter 620 (i.e., the length from hub 628 tothe distal tip of catheter shaft 622) remains constant. In someinstances, catheter shaft 622 may include a detent and/or retainingmechanism that helps to hold slidable member 634 at the first position.

Slidable member 634 may be slid proximally to a second position such asuntil second stop 638 is disposed at landing region 646, as shown inFIG. 14. This may include abutting second stop 638 with landing region646 or positioning second stop 638 within or along landing region 646.Doing so may define a second working length L2 of catheter shaft 622that can extend into guide catheter 11. The second working length L2 maybe greater than the first working length L1. In some instances, secondworking length L2 may correspond to an intermediate working length ofcatheter shaft 622 that can extend into guide catheter. Thus, whenretainer 626 is oriented as shown in FIG. 14, trap balloon catheter 620may be compatible with a second guide catheter having a working lengthgreater than the working length of the first guide catheter (e.g., a 100cm guide catheter). When slidable member 634 is positioned at the secondposition (corresponding to use of trap balloon catheter 620 with a guidecatheter having a specified working length (e.g., a 100 cm guidecatheter)), the full working length L2 of trap balloon catheter 620 canbe inserted into the lumen of the guide catheter having the specifiedworking length while balloon 624 remains within the lumen of the guidecatheter and is prevented from extending out the distal end of the guidecatheter. In some instances, catheter shaft 622 may include a detentand/or retaining mechanism that helps to hold slidable member 634 at thesecond position.

Slidable member 634 may be slid further proximally (e.g., where secondstop 638 is disposed proximally of landing region 646) to a thirdposition such as until first stop 636 abuts or nests with distal endregion 644, as shown in FIG. 15. This defines a third working length L3of catheter shaft 622 that can extend into guide catheter 11. The thirdworking length L3 may correspond to the longest working length ofcatheter shaft 622 that can extend into guide catheter 11. In someinstances, catheter shaft 622 may include a detent and/or retainingmechanism that helps to hold slidable member 634 at the third position.

In some instances, positioning slidable member 634 at the secondposition, shown in FIG. 14, may position balloon 624 a relatively shortdistance proximally of the distal end of the guide catheter (e.g., whenused with a 100 cm guide catheter). It may be desirable to shift balloon624 distally within the guide catheter to a position adjacent to thedistal end of the guide catheter. Shifting slidable member 634 to thethird position (e.g., when retainer 626 is oriented as shown in FIG. 15)may elongate the working length of catheter shaft 622 such that balloon624 is positioned at the distal end of the guide catheter, yetengagement of first stop 636 with hub of guide catheter 11 prevents theballoon 624 from extending out distal end of guide catheter 11. In someinstances, moving slidable member 634 from second position to the thirdposition may elongate the working length of catheter shaft 622 anadditional 2-10 cm (e.g., about 5 cm). It can be appreciated that anumber of additional lengths/adjustments are contemplated beyond what isshown. For example, sheath 640 may include a number of additionaldiscrete positions such as landing regions that allow for greater lengthvariability.

It is noted that catheter shaft 622 maintains a constant overall lengthX (i.e., the length measured from the hub 628 to the distal tip of thecatheter shaft 622) regardless of which position the slidable member 634is at. For example, the overall length X of the catheter shaft 622 ofcatheter 620 when slidable member 634 is positioned at the firstposition, providing a first working length L1, may be the same as theoverall length X of catheter shaft 622 of catheter 620 when slidablemember 634 is positioned at the second position, providing a secondworking length L2, greater than the first working length L1.Furthermore, the overall length X of catheter shaft 622 of catheter 620when slidable member 634 is positioned at the second position, providinga second working length L2, may be the same as the overall length X ofcatheter shaft 622 of catheter 620 when slidable member 634 ispositioned at the third position, providing a third working length L3,greater than the second working length L2.

Catheter shaft 622 and/or slidable member 634 may include one or morevisual markings that may aid a user in assessing whichposition/configuration that slidable member 634 is in and, thus, whichlength of guide catheter that trap balloon catheter 620 may becompatible with to insure balloon 624 is prevented from being positioneddistal of the guide catheter when fully inserted into the guidecatheter. For example, slidable member 634 may include a visual marker637 a positioned distally of second stop 638 that is visible (e.g.,exposed or otherwise uncovered by sheath 640) when slidable member 634is in the first position. In some of these and in other embodiments,catheter shaft 622 may include a visual marker such as a visual marker637 b. Visual marker 637 b may be visible and generally positioneddistally of and adjacent to first stop 636 when slidable member 634 isin the first position. In some of these and in other embodiments,slidable member 634 may include a visual marker 637 d that is positioneddistally of second stop 638 that is visible (e.g., exposed or otherwiseuncovered by sheath 640) when slidable member 634 is in the secondposition. In some of these and in other embodiments, catheter shaft 622may include a visual marker 637 c that may be visible and generallypositioned distally of and adjacent to first stop 636 when slidablemember 634 is in the second position. In some of these and in otherembodiments, catheter shaft 622 may include a visual marker 637 e thatmay be visible and generally positioned distally of and adjacent tofirst stop 636 when slidable member 634 is in the third position. It canbe appreciated that any number and/or combinations of visual markers(e.g., visual markers along slidable member 634, visual markers alongcatheter shaft 622, or both) may be utilized including those disclosedherein to provide a visual indication and confirmation of which positionthe slidable member 634 is positioned. The visual marker(s) may insurethe correct working length of the trap balloon catheter 620 is set foruse with a guide catheter of a specified corresponding working length.Other arrangements are contemplated.

While the adjustable working lengths for trap balloon catheter 620 maybe adjusted to be used with 90 cm and 100 cm guide catheters as examplesin cardiology, these lengths are not intended to be limiting. Thedesired trapping position and/or working length for trap ballooncatheter 620 may vary. For example, in some instances it may bedesirable to configure the working length of trap balloon catheter 620so that the distal end thereof (and/or balloon 624) is positioned at,adjacent, or just proximal to a distal curve in the guide catheter,which may be about 5 cm or so from the distal end of the guide catheter.In some of these and in other instances it may be desirable to adjustthe working length of trap balloon catheter 620 to about 97 cm +/−1 cm(which may be effective for use with a 90 cm guide catheter with ahemostatic valve), to about 107 cm +/−1 cm (which may be effective foruse with a 100 cm guide catheter with a hemostatic valve), to about 112cm +/−1 cm (which may be effective for positioning the distal end oftrap balloon catheter 620 adjacent to, but without exiting, the distalend of a 100 cm guide catheter with a hemostatic valve), or othersuitable lengths. These are just examples. Other lengths arecontemplated.

The materials that can be used for the various components of system 10(and/or other systems and/or trap balloon catheters and/or retainersdisclosed herein) may include those commonly associated with medicaldevices. For simplicity purposes, the following discussion makesreference to trap balloon catheter 20. However, this is not intended tolimit the devices and methods described herein, as the discussion may beapplied to other similar tubular members and/or components of tubularmembers or devices disclosed herein.

Trap balloon catheter 20 and/or other trap balloon catheters disclosedherein may be made from a metal, metal alloy, polymer (some examples ofwhich are disclosed below), a metal-polymer composite, ceramics,combinations thereof, and the like, or other suitable material. Someexamples of suitable polymers may include polytetrafluoroethylene(PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylenepropylene (FEP), polyoxymethylene (POM, for example, DELRIN® availablefrom DuPont), polyether block ester, polyurethane (for example,Polyurethane 85A), polypropylene (PP), polyvinylchloride (PVC),polyether-ester (for example, ARNITEL® available from DSM EngineeringPlastics), ether or ester based copolymers (for example,butylene/poly(alkylene ether) phthalate and/or other polyesterelastomers such as HYTREL® available from DuPont), polyamide (forexample, DURETHAN® available from Bayer or CRISTAMID® available from ElfAtochem), elastomeric polyamides, block polyamide/ethers, polyetherblock amide (PEBA, for example available under the trade name PEBAX®),ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE),Marlex high-density polyethylene, Marlex low-density polyethylene,linear low density polyethylene (for example REXELL®), polyester,polybutylene terephthalate (PBT), polyethylene terephthalate (PET),polytrimethylene terephthalate, polyethylene naphthalate (PEN),polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI),polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (for example, KEVLAR®), polysulfone,nylon, nylon-12 (such as GRILAMID® available from EMS American Grilon),perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin,polystyrene, epoxy, polyvinylidene chloride (PVdC),poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and/or SIBS50A), polycarbonates, ionomers, biocompatible polymers, other suitablematerials, or mixtures, combinations, copolymers thereof, polymer/metalcomposites, and the like.

Some examples of suitable metals and metal alloys include stainlesssteel, such as 304V, 304L, and 316LV stainless steel; mild steel;nickel-titanium alloy such as linear-elastic and/or super-elasticnitinol; other nickel alloys such as nickel-chromium-molybdenum alloys(e.g., UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY®C-22®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys,and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL®400, NICKELVAC® 400, NICORROS® 400, and the like),nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such asMP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 suchas HASTELLOY® ALLOY B2®), other nickel-chromium alloys, othernickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-ironalloys, other nickel-copper alloys, other nickel-tungsten or tungstenalloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenumalloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like);platinum enriched stainless steel; titanium; combinations thereof; andthe like; or any other suitable material.

As alluded to herein, within the family of commercially availablenickel-titanium or nitinol alloys, is a category designated “linearelastic” or “non-super-elastic” which, although may be similar inchemistry to conventional shape memory and super elastic varieties, mayexhibit distinct and useful mechanical properties. Linear elastic and/ornon-super-elastic nitinol may be distinguished from super elasticnitinol in that the linear elastic and/or non-super-elastic nitinol doesnot display a substantial “superelastic plateau” or “flag region” in itsstress/strain curve like super elastic nitinol does. Instead, in thelinear elastic and/or non-super-elastic nitinol, as recoverable strainincreases, the stress continues to increase in a substantially linear,or a somewhat, but not necessarily entirely linear relationship untilplastic deformation begins or at least in a relationship that is morelinear that the super elastic plateau and/or flag region that may beseen with super elastic nitinol. Thus, for the purposes of thisdisclosure linear elastic and/or non-super-elastic nitinol may also betermed “substantially” linear elastic and/or non-super-elastic nitinol.

In some cases, linear elastic and/or non-super-elastic nitinol may alsobe distinguishable from super elastic nitinol in that linear elasticand/or non-super-elastic nitinol may accept up to about 2-5% strainwhile remaining substantially elastic (e.g., before plasticallydeforming) whereas super elastic nitinol may accept up to about 8%strain before plastically deforming. Both of these materials can bedistinguished from other linear elastic materials such as stainlesssteel (that can also can be distinguished based on its composition),which may accept only about 0.2 to 0.44 percent strain beforeplastically deforming.

In some embodiments, the linear elastic and/or non-super-elasticnickel-titanium alloy is an alloy that does not show anymartensite/austenite phase changes that are detectable by differentialscanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA)analysis over a large temperature range. For example, in someembodiments, there may be no martensite/austenite phase changesdetectable by DSC and DMTA analysis in the range of about −60 degreesCelsius (° C.) to about 120° C. in the linear elastic and/ornon-super-elastic nickel-titanium alloy. The mechanical bendingproperties of such material may therefore be generally inert to theeffect of temperature over this very broad range of temperature. In someembodiments, the mechanical bending properties of the linear elasticand/or non-super-elastic nickel-titanium alloy at ambient or roomtemperature are substantially the same as the mechanical properties atbody temperature, for example, in that they do not display asuper-elastic plateau and/or flag region. In other words, across a broadtemperature range, the linear elastic and/or non-super-elasticnickel-titanium alloy maintains its linear elastic and/ornon-super-elastic characteristics and/or properties.

In some embodiments, the linear elastic and/or non-super-elasticnickel-titanium alloy may be in the range of about 50 to about 60 weightpercent nickel, with the remainder being essentially titanium. In someembodiments, the composition is in the range of about 54 to about 57weight percent nickel. One example of a suitable nickel-titanium alloyis FHP-NT alloy commercially available from Furukawa Techno Material Co.of Kanagawa, Japan. Some examples of nickel titanium alloys aredisclosed in U.S. Pat. Nos. 5,238,004 and 6,508,803, which areincorporated herein by reference. Other suitable materials may includeULTANIUM™ (available from Neo-Metrics) and GUM METAL™ (available fromToyota). In some other embodiments, a superelastic alloy, for example asuperelastic nitinol can be used to achieve desired properties.

In at least some embodiments, portions or all of trap balloon catheter20 may also be doped with, made of, or otherwise include a radiopaquematerial. Radiopaque materials are understood to be materials capable ofproducing a relatively bright image on a fluoroscopy screen or anotherimaging technique during a medical procedure. This relatively brightimage aids the user of trap balloon catheter 20 in determining itslocation. Some examples of radiopaque materials can include, but are notlimited to, gold, platinum, palladium, tantalum, tungsten alloy, polymermaterial loaded with a radiopaque filler, and the like. Additionally,other radiopaque marker bands and/or coils may also be incorporated intothe design of trap balloon catheter 20 to achieve the same result.

In some embodiments, a degree of Magnetic Resonance Imaging (MRI)compatibility is imparted into trap balloon catheter 20. For example,trap balloon catheter 20, or portions thereof, may be made of a materialthat does not substantially distort the image and create substantialartifacts (e.g., gaps in the image). Certain ferromagnetic materials,for example, may not be suitable because they may create artifacts in anMRI image. Trap balloon catheter 20, or portions thereof, may also bemade from a material that the MRI machine can image. Some materials thatexhibit these characteristics include, for example, tungsten,cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®,PHYNOX®, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g.,UNS: R30035 such as MP35-N® and the like), nitinol, and the like, andothers. It should be understood that this disclosure is, in manyrespects, only illustrative.

Changes may be made in details, particularly in matters of shape, size,and arrangement of steps without exceeding the scope of the disclosure.This may include, to the extent that it is appropriate, the use of anyof the features of one example embodiment being used in otherembodiments. The invention's scope is, of course, defined in thelanguage in which the appended claims are expressed.

What is claimed is:
 1. A method of using a trap balloon catheter,comprising: inserting a guidewire into a lumen; advancing a guidecatheter into the lumen over the guidewire, the guide catheter having aworking length; adjusting a working length of a trap balloon catheterbased on the working length of the guide catheter, the trap ballooncatheter comprising: a catheter shaft extending from a proximal hub to adistal tip, the catheter shaft having an overall length that is fixed; atrap balloon attached to a distal region of the catheter shaft, the trapballoon being configured for expansion within the guide catheter tosecure the guidewire between the trap balloon and an inner surface ofthe guide catheter; and a trap balloon retainer coupled to the cathetershaft, the trap balloon retainer including a slidable memberpositionable over the catheter shaft in a first position defining afirst working length of the trap balloon catheter and a second positiondefining a second working length of the trap balloon catheter, thesecond working length of the trap balloon catheter being longer than thefirst working length of the trap balloon catheter; wherein the workinglength of the trap balloon catheter is configured to prevent the trapballoon from being positioned distal of a distal end of the guidecatheter when the trap balloon catheter is fully advanced distallywithin the guide catheter up to the working length of the trap ballooncatheter; and advancing the trap balloon catheter distally within theguide catheter.
 2. The method of claim 1, further comprising expandingthe trap balloon within the guide catheter to secure the guidewirebetween the trap balloon and the inner surface of the guide catheter. 3.The method of claim 2, further comprising advancing a treatment catheterthrough the guide catheter on the guidewire.
 4. The method of claim 3,further comprising: prior to expanding the trap balloon, withdrawing adistal end of the treatment catheter to a position proximal of a distalend of the guide catheter.
 5. The method of claim 1, wherein the trapballoon catheter is configured for use within a plurality of differentworking length guide catheters.
 6. The method of claim 1, wherein thetrap balloon catheter is adjustable to position the trap balloon about 5cm proximal of the distal end of the guide catheter when the trapballoon catheter is fully advanced distally within the guide catheter upto the working length of the trap balloon catheter.
 7. The method ofclaim 1, wherein the slidable member is positionable over the cathetershaft in a third position defining a third working length of the trapballoon catheter, the third working length of the trap balloon catheterbeing longer than the second working length of the trap ballooncatheter.
 8. The method of claim 1, wherein the overall length of thecatheter shaft is constant in all positions of the slidable member overthe catheter shaft.
 9. The method of claim 1, wherein the trap ballooncatheter further comprises a sheath fixed to the catheter shaft andsurrounding a proximal end region of the slidable member.
 10. The methodof claim 9, wherein the trap balloon catheter further comprises: a firststop located on a distal end region of the slidable member; and a secondstop located on the proximal end region of the slidable member; whereinthe first stop is positioned distal of the sheath and the second stop ispositioned within the sheath.
 11. The method of claim 10, wherein thefirst stop is configured to abut a proximal end of the guide catheterwhen the trap balloon catheter is fully advanced distally within theguide catheter up to the working length of the trap balloon catheter.12. The method of claim 10, wherein the sheath includes: a distal endregion having a reduced outer diameter; and a landing region having areduced inner diameter disposed proximally of the distal end region ofthe sheath.
 13. The method of claim 12, wherein the second stop isconfigured to engage the distal end region of the sheath when theslidable member is in the first position.
 14. The method of claim 12,wherein the second stop is configured to engage the landing region whenthe slidable member is in the second position.
 15. The method of claim1, wherein the catheter shaft or the slidable member includes one ormore visual markings indicating which position the slidable member isin.
 16. The method of claim 4, further comprising: after expanding thetrap balloon, withdrawing the treatment catheter from the guide catheterwhile maintaining the guidewire in a fixed position.
 17. The method ofclaim 16, further comprising: after withdrawing the treatment catheterfrom the guide catheter, advancing a second treatment catheter throughthe guide catheter on the guidewire.
 18. The method of claim 17, furthercomprising: after advancing the second treatment catheter, deflating thetrap balloon and removing the trap balloon catheter from the guidecatheter.
 19. The method of claim 18, further comprising: afterdeflating the trap balloon, advancing the second treatment catheter outof the distal end of the guide catheter.
 20. A method of using a trapballoon catheter, comprising: selecting a working length of a trapballoon catheter to from a first working length or a second workinglength based on a working length of a guide catheter, the second workinglength of the trap balloon catheter being longer than the first workinglength of the trap balloon catheter, the trap balloon cathetercomprising: a catheter shaft extending from a proximal hub to a distaltip, the catheter shaft having an overall length that is fixed; a trapballoon attached to a distal region of the catheter shaft, the trapballoon being configured for expansion within the guide catheter tosecure a guidewire between the trap balloon and an inner surface of theguide catheter; and a trap balloon retainer coupled to the cathetershaft, the trap balloon retainer being movable between a first positionto define the first working length of the trap balloon catheter and asecond position to define the second working length of the trap ballooncatheter; advancing the trap balloon catheter distally through a lumenof the guide catheter and alongside the guidewire with the trap balloonin a deflated state, wherein the working length of the trap ballooncatheter is configured to prevent the trap balloon from being positioneddistal of a distal end of the guide catheter when the trap ballooncatheter is fully advanced distally within the guide catheter up to theselected working length of the trap balloon catheter; and inflating thetrap balloon within the lumen of the guide catheter to press theguidewire against the inner surface of the guide catheter.